Office of Extramural Research 
Officer Evaluation Report 
Office of Exploratory Research 
Oxygen Enhancement Ratio 
Office of Energy Research 
Open Educational Resources 
Operating Expense Ratio 
Optimized Edge Routing 
oestrogen receptor 
Office of Emergency Response 
Office of Employee Relations 
Office of Environmental Restoration 
Office of External Relations 
Officer Effectiveness Report 
Officer Efficiency Report 
Officer Evaluation Reports 
Open Education Resource 
operating experience report 
Operation Expense Ratio 
Operational ELINT Requirements 
Operational Equipment Requirement 
Optical and Electronic Research 
Oracle Enterprise Repository 
Organizational Efficiency Review 
oxygen enhancement ratios 
Oxygen Evolution Reaction 
oxygen extraction 
oxygen extraction ratio 
Open Educational Resource